Flooding in Ohio, January 1 to 20, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CLEVELAND OHIO
349 PM EST SAT JAN 1 2005

.SHORT TERM (TONIGHT THRU MONDAY)...

A VERY CHALLENGING FORECAST OVER THE NEXT SVRL DAYS WITH SVRL
COMPLEX ISSUES TO CONTEND WITH AS A FRONT BECOMES STATIONARY OVER
OHIO BY MONDAY.

DEVELOPING LOW PRES OVER THE SRN PLAINS WILL MOVE TO THE WESTERN
LAKES BY TONIGHT. THIS WILL ALLOW THE WARM FRONT OVER KY TO MOVE NWD
THIS EVENING...SPREADING PCPN ACROSS THE ENTIRE AREA. GFS SEEMS TO
BE HANDLING AREA OF PCPN BETTER OVER KY AND IN COMPARED TO THE ETA.
THE STRONG 850MB MOISTURE CVRG ALIGNS QUITE WELL WITH THE PCPN ECHOS
ON THE RADAR MOSAIC. THE GFS SHOWS THE PCPN MOVING E AND NWD OVER
THE AREA TONIGHT. DOUBTFUL THAT PCPN WILL BE HVY...BUT MOST AREAS
WILL HAVE LIGHT PCPN OVERNIGHT. CURRENT FCSTS HAVE LKLY POPS...AND
THIS SEEMS REASONABLE WITH STRONG ISENTROPIC LIFT NOTED BY THE GFS.
ANOTHER CONCERN FOR TNGT IS PCPN TYPE INITIALLY. ETA AND GFS
SOUNDINGS BOTH SUPPORT THAT LOW LVL TEMPS MAY BE NR FRZ AT THE ONSET
OF THE PCPN AT TOL. THIS SEEMS REASONABLE GIVEN THE DRY AIRMASS IN
PLACE OVER TOL AND COOL/DRY NELY FLOW WHICH WILL REMAIN IN PLACE
THRU THE EVENING. PCPN WILL LIKELY FALL INTO DWPTS THAT ARE IN THE
MID 20S WHICH SHOULD ALLOW FOR A BRIEF PERIOD OF MIXED RAIN/ZR AT
TOL. UNCERTAIN ABOUT NW PA AS THEY MAY SEE THE COOL AIR SCOURED OUT
BEFORE THE PCPN ARRIVES (IT WILL ARRIVE LATER AT ERI).
HOWEVER...THAT AREA WILL ALSO HAVE A COUPLE OF HOURS OF EXTRA
NIGHTTIME COOLING AS WELL...SO HAVE OPTED TO GO WITH A ZR/R MIX AT
THE ONSET IN NW PA AS WELL.

AS FOR THE FLOODING SITUATION ON AREA RIVERS...MOST RIVERS ARE AT OR
NR CREST...OR EVEN STARTING TO SUBSIDE. DOUBTFUL TONIGHTS PCPN WILL
AMT TO MUCH...MAYBE A QUARTER OF AN INCH IN A FEW AREAS. PCPN ON
SUNDAY WILL ALSO BE A QUARTER OF AN INCH OR SO. HOWEVER...IT MUST BE
NOTED THAT IF ANY PLACE SEES MORE PCPN THAN FCST...RIVERS IN THAT
AREA COULD START TO RISE AGAIN.

ONCE THE WARM FRONT MOVES THRU LATE TONIGHT/TMRW AM...MOST OF THE
FORECAST AREA WILL BE DRY UNTIL THE COLD FRONT MOVES THRU TMRW AFTN.
TOUGH FCST FOR TMRW AS MOS POPS ARE GOING LIKELY OR
CATEGORICAL...HOWEVER THERE WILL LIKELY BE JUST A LINE OF SHOWERS
IMMEDIATELY AHEAD OF THE FRONT...NOT AN ALL DAY TYPE RAIN (SIMILAR
TO FRI MORNING SYSTEM). TRIED TO TIME THE PCPN WITH THE FRONTAL
PASSAGE...MAINLY LATE MORNING/EARLY AFTN WEST AND AFTN/EVENING EAST.
TIMING FROM THE ETA AND GFS VERY CONSISTENT...SO THIS TYPE OF
SCENARIO SEEMS REASONABLE. IN FACT...TIMING MAY NEED TO BE DELAYED
EVEN FURTHER IF THE MDLS CONTINUE TO SLOW THE MOVEMENT OF THE FRONT.
TEMPS WILL BE THE BIG STORY FOR TMRW AS MANY PLACES WILL RISE TO NR
60S WITH 850MB TEMPS RISING TO +7C.

FRONT BECOMES STNRY OVER SRN OH SUN NIGHT/MON MORNING WHILE A SHORT
WAVE EJECTS INTO THE PLAINS ALLOWING A SFC WAVE TO DEVELOP ALONG THE
FRONT. THIS ULTIMATELY ALLOWS THE BAROCLINIC ZONE TO STRENGTHEN OVER
THE AREA WHILE THE WAVE MOVES TOWARD OH MONDAY. AS THIS WAVE
APPROACHES...PLENTY OF ISENTROPIC LIFT AND WARM ADVECTION ALOFT WILL
ALLOW FOR RAIN TO AGAIN FALL. THIS RAINFALL WILL BE A MORE
SIGNIFICANT WITH BETTER JET DYNAMICS AND BETTER MOISTURE. THE GFS
SHOWS UP TO AN INCH QPF MON/MON NIGHT. WITH RIVERS ALREADY NEAR
BANKFULL...THIS QPF WILL CERTAINLY NEED TO BE WATCHED. FLOOD WATCHES
MAY BE NEEDED SUNDAY TO ADDRESS THIS SITUATION. FOR NOW...WILL ISSUE
A HYDROLOGIC OUTLOOK TO ADDRESS THE SITUATION. TOUGH CALL ON TEMPS
MON AS IT ALL DEPENDS WHERE THE FRONT SETS UP. WILL LIKELY BE A 20
DEG OR SO TEMP DIFF IN OHIO ON MON. COULD SEE THE NORTH IN THE UPR
30S...WHILE AREAS NR THE OH RIVER WILL BE IN THE 50S.

&&

.LONG TERM (TUE THRU SAT)...
THE GFS AND OTHER MODELS ARE IN GOOD AGREEMENT THAT A STRONG
BAROCLINIC ZONE WILL CONTINUE OVR THE OH VLY REGION THRU THU.
HOWEVER...EVEN THOUGH THE MDLS ARE IN GOOD GENERAL AGREEMENT...THE
EXTENDED FCST IRONICALLY IS QUITE CHALLENGING. TOUGH CALL WHERE THE
FRONT WILL SET UP THIS WEEK...BUT ALL MDL GUIDANCE WOULD SUGGEST
THAT IT WILL STAY S OF THE FORECAST AREA...ALLOWING NRN OH/NW PA TO
BE ON THE COOL SIDE OF THE FRONT. THIS IS REFLECTED IN THE LATEST
MOS GUIDANCE FOR MID WEEK...SHOWING COOLER TEMPS. HOWEVER...THERE
WILL LIKELY BE A 15-25 DEG TEMP SWING ACROSS THE FRONT AS THE
BOUNDARY WILL HAVE QUITE A TIGHT TEMP GRADIENT. UNFORTUNATELY...WITH
THE FRONT BEING IN THE PROXIMITY...ANY VARIATION N OR S COULD LEAD
TO A LARGE ERROR IN TEMPS. THEREFORE...CONFIDENCE IN THE TEMPS FCST
FOR THE TUE-THU TIME PERIOD IS SOMEWHAT LOW. AM CONCERNED THAT MOS
GUIDANCE MAY BE TOO HIGH. THE GFS 10M TEMPS HAVE TEMPS IN THE 30S
WITH PLENTY OF COLD LOW LVL AIR FILTERING INTO THE AREA FROM THE N.
NOT WANTING TO GO TOO LOW...HAVE OPTED TO GO WITH THE ENSEMBLE MOS
MEAN VALUES FOR NOW...AND SEE EXACTLY WHAT WILL HAPPEN WITH THIS
FRONT AS TIME GOES ON. PCPN WILL ALSO BE ABUNDANT JUST N OF THE
FRONT. WITH THE GFS SAGGING THE FRONT A LITTLE FARTHER S...THINK
THAT THE BEST PCPN WILL BE TUE NIGHT/WED AS THE NEXT WAVE RIDES
ALONG THE FRONT. IF ENOUGH COLD AIR CAN SAG FAR ENOUGH SOUTH...PCPN
TYPE WILL ALSO BECOME A FACTOR...ESPECIALLY TUE NIGHT THRU WED
NIGHT. GFS AND DGEX SUPPORT POSSIBLE MIXED PCPN FAR N...AND WILL
NEED TO INCLUDE THIS IN THE FCST FOR THE NRN TIER. PLENTY OF
UNCERTAINTY IN THE EXTENDED. FORTUNATELY...IT LOOKS LIKE BY THU AFTN
THE FRONT WILL MOVE THRU THE AREA AND IT WILL DRY OUT SIGNIFICANTLY
AS HIGH PRES BUILDS INTO THE REGION. IT MAY BE COLD ENOUGH THU
AFTN/NIGHT FOR SOME LES...BUT HIGH PRES WILL LIKELY BE STRONG ENOUGH
TO NOT LET IT GET OUT OF HAND. ALTHOUGH THIS COOLER WX ON THU WILL
BE BRIEF AS ANOTHER WARM FRONT APPROACHES THE AREA BY SAT EVENING.

&&

.AVIATION (18Z-18Z)...
HI PRES OFF TO THE E ALLOWING CLDS TO INCRS AND LWR FRM THE W-SW IN
ADVC OF A WRMFNT THRU THE OH RVR VLY. CIGS TO LWR QUICKLY THIS EVENG
TO MVFR AND THEN IFR AFT MIDN AS RN & FOG DVLP AND SPRD EWRD. WNDS
TO SHIFT NE-E TO THE SE-S TWD MRNG AS THE WRMFNT APCHS. FNT TO LIFT
NE OF THE AREA DURG SUN TURNING THE WINDS INTO THE SW AND INCRS.
CIG/VSBYS MNLY IFR DURG THE PREDAWN & ERY MRNG HRS THEN IMPROV
SOMEWHAT TO MVFR WI A PROJECTED DRY SLOT BFR ANTHER BATCH OF RN
DVLPS DURG THE DAY SUN.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.

&&

SHORT TERM...MRD
LONG TERM...MRD
AVIATION...20